MacPhee, John A. published the artcileSteric limits to ester alkylation; synthesis of highly hindered esters via hexamethylphosphoramide-favored enolization, SDS of cas: 5340-78-3, the publication is Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (1977), 694-6, database is CAplus.
The steric limits to alkylation of carboxylic esters by alkyl iodides with LiN(CHMe2)2 as base in the presence of (Me2N)3PO were studied using a modification of R. H. Schlessinger et al. (1973) and the influence of (Me2N)3PO inpromoting ester enolization, as opposed to its influence on the alkylation step, was examined The formation of α,α-disubstituted from α-monosubstituted esters takes place in high yield and is only slightly influenced by the nature of the alkylating agent, whereas the formation of α,α,α-trisubstituted from α,α-disubstituted esters is sensitive to the steric nature of the ester to be alkylated. Thus in the synthesis of trisubstituted from monosubstituted esters the order of introduction of alkyl groups is critical. The failure of esters to react is interpreted by an inability to undergo enolization.
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, SDS of cas: 5340-78-3.
Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics